<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
</head>
<body>
   <div id="app">
       <textarea v-model="nickname" style="width:500px;height:500px;float:left;"></textarea>
       <div v-html="nickname" style="width:500px;height:500px;float:right;border:1px solid red;"></div>

   </div>
    
    <script src="js/vue.js"></script>
    <script>
      Vue.config.devtools = false
      Vue.config.productionTip = false
        new Vue({
            el:"#app",
            data(){
                return{
                    nickname:"",
                    str:"123"

                }
            },
            methods:{


            },
            mounted(){
                this.str =this.str.replace( / /g,"")
                console.log(this.str)
                let i =0
              let timer= setInterval(() => {
                this.nickname +=this.str[i++]
                if(i===this.str.length){
                    clearInterval(timer)
                }
               }, 100);


            }
        })
    
    
    
    
    </script>
</body>
</html>